nm: Add --quiet to suppress "no symbols" diagnostic
[binutils-gdb.git] / gdb / osabi.c
blobb1603c09c8553bf49530683ed0f57909f10690eb
1 /* OS ABI variant handling for GDB.
3 Copyright (C) 2001-2021 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
20 #include "defs.h"
22 #include "osabi.h"
23 #include "arch-utils.h"
24 #include "gdbcmd.h"
25 #include "command.h"
26 #include "gdb_bfd.h"
28 #include "elf-bfd.h"
30 #ifndef GDB_OSABI_DEFAULT
31 #define GDB_OSABI_DEFAULT GDB_OSABI_UNKNOWN
32 #endif
34 /* State for the "set osabi" command. */
35 static enum { osabi_auto, osabi_default, osabi_user } user_osabi_state;
36 static enum gdb_osabi user_selected_osabi;
37 static const char *gdb_osabi_available_names[GDB_OSABI_INVALID + 3] = {
38 "auto",
39 "default",
40 "none",
41 NULL
43 static const char *set_osabi_string;
45 /* Names associated with each osabi. */
47 struct osabi_names
49 /* The "pretty" name. */
51 const char *pretty;
53 /* The triplet regexp, or NULL if not known. */
55 const char *regexp;
58 /* This table matches the indices assigned to enum gdb_osabi. Keep
59 them in sync. */
60 static const struct osabi_names gdb_osabi_names[] =
62 { "unknown", NULL },
63 { "none", NULL },
65 { "SVR4", NULL },
66 { "GNU/Hurd", NULL },
67 { "Solaris", NULL },
68 { "GNU/Linux", "linux(-gnu[^-]*)?" },
69 { "FreeBSD", NULL },
70 { "NetBSD", NULL },
71 { "OpenBSD", NULL },
72 { "WindowsCE", NULL },
73 { "DJGPP", NULL },
74 { "QNX-Neutrino", NULL },
75 { "Cygwin", NULL },
76 { "Windows", NULL },
77 { "AIX", NULL },
78 { "DICOS", NULL },
79 { "Darwin", NULL },
80 { "OpenVMS", NULL },
81 { "LynxOS178", NULL },
82 { "Newlib", NULL },
83 { "SDE", NULL },
84 { "PikeOS", NULL },
86 { "<invalid>", NULL }
89 const char *
90 gdbarch_osabi_name (enum gdb_osabi osabi)
92 if (osabi >= GDB_OSABI_UNKNOWN && osabi < GDB_OSABI_INVALID)
93 return gdb_osabi_names[osabi].pretty;
95 return gdb_osabi_names[GDB_OSABI_INVALID].pretty;
98 /* See osabi.h. */
100 const char *
101 osabi_triplet_regexp (enum gdb_osabi osabi)
103 if (osabi >= GDB_OSABI_UNKNOWN && osabi < GDB_OSABI_INVALID)
104 return gdb_osabi_names[osabi].regexp;
106 return gdb_osabi_names[GDB_OSABI_INVALID].regexp;
109 /* Lookup the OS ABI corresponding to the specified target description
110 string. */
112 enum gdb_osabi
113 osabi_from_tdesc_string (const char *name)
115 int i;
117 for (i = 0; i < ARRAY_SIZE (gdb_osabi_names); i++)
118 if (strcmp (name, gdb_osabi_names[i].pretty) == 0)
120 /* See note above: the name table matches the indices assigned
121 to enum gdb_osabi. */
122 enum gdb_osabi osabi = (enum gdb_osabi) i;
124 if (osabi == GDB_OSABI_INVALID)
125 return GDB_OSABI_UNKNOWN;
126 else
127 return osabi;
130 return GDB_OSABI_UNKNOWN;
133 /* Handler for a given architecture/OS ABI pair. There should be only
134 one handler for a given OS ABI each architecture family. */
135 struct gdb_osabi_handler
137 struct gdb_osabi_handler *next;
138 const struct bfd_arch_info *arch_info;
139 enum gdb_osabi osabi;
140 void (*init_osabi)(struct gdbarch_info, struct gdbarch *);
143 static struct gdb_osabi_handler *gdb_osabi_handler_list;
145 void
146 gdbarch_register_osabi (enum bfd_architecture arch, unsigned long machine,
147 enum gdb_osabi osabi,
148 void (*init_osabi)(struct gdbarch_info,
149 struct gdbarch *))
151 struct gdb_osabi_handler **handler_p;
152 const struct bfd_arch_info *arch_info = bfd_lookup_arch (arch, machine);
153 const char **name_ptr;
155 /* Registering an OS ABI handler for "unknown" is not allowed. */
156 if (osabi == GDB_OSABI_UNKNOWN)
158 internal_error
159 (__FILE__, __LINE__,
160 _("gdbarch_register_osabi: An attempt to register a handler for "
161 "OS ABI \"%s\" for architecture %s was made. The handler will "
162 "not be registered"),
163 gdbarch_osabi_name (osabi),
164 bfd_printable_arch_mach (arch, machine));
165 return;
168 gdb_assert (arch_info);
170 for (handler_p = &gdb_osabi_handler_list; *handler_p != NULL;
171 handler_p = &(*handler_p)->next)
173 if ((*handler_p)->arch_info == arch_info
174 && (*handler_p)->osabi == osabi)
176 internal_error
177 (__FILE__, __LINE__,
178 _("gdbarch_register_osabi: A handler for OS ABI \"%s\" "
179 "has already been registered for architecture %s"),
180 gdbarch_osabi_name (osabi),
181 arch_info->printable_name);
182 /* If user wants to continue, override previous definition. */
183 (*handler_p)->init_osabi = init_osabi;
184 return;
188 (*handler_p) = XNEW (struct gdb_osabi_handler);
189 (*handler_p)->next = NULL;
190 (*handler_p)->arch_info = arch_info;
191 (*handler_p)->osabi = osabi;
192 (*handler_p)->init_osabi = init_osabi;
194 /* Add this OS ABI to the list of enum values for "set osabi", if it isn't
195 already there. */
196 for (name_ptr = gdb_osabi_available_names; *name_ptr; name_ptr ++)
198 if (*name_ptr == gdbarch_osabi_name (osabi))
199 return;
201 *name_ptr++ = gdbarch_osabi_name (osabi);
202 *name_ptr = NULL;
206 /* Sniffer to find the OS ABI for a given file's architecture and flavour.
207 It is legal to have multiple sniffers for each arch/flavour pair, to
208 disambiguate one OS's a.out from another, for example. The first sniffer
209 to return something other than GDB_OSABI_UNKNOWN wins, so a sniffer should
210 be careful to claim a file only if it knows for sure what it is. */
211 struct gdb_osabi_sniffer
213 struct gdb_osabi_sniffer *next;
214 enum bfd_architecture arch; /* bfd_arch_unknown == wildcard */
215 enum bfd_flavour flavour;
216 enum gdb_osabi (*sniffer)(bfd *);
219 static struct gdb_osabi_sniffer *gdb_osabi_sniffer_list;
221 void
222 gdbarch_register_osabi_sniffer (enum bfd_architecture arch,
223 enum bfd_flavour flavour,
224 enum gdb_osabi (*sniffer_fn)(bfd *))
226 struct gdb_osabi_sniffer *sniffer;
228 sniffer = XNEW (struct gdb_osabi_sniffer);
229 sniffer->arch = arch;
230 sniffer->flavour = flavour;
231 sniffer->sniffer = sniffer_fn;
233 sniffer->next = gdb_osabi_sniffer_list;
234 gdb_osabi_sniffer_list = sniffer;
238 enum gdb_osabi
239 gdbarch_lookup_osabi (bfd *abfd)
241 struct gdb_osabi_sniffer *sniffer;
242 enum gdb_osabi osabi, match;
243 int match_specific;
245 /* If we aren't in "auto" mode, return the specified OS ABI. */
246 if (user_osabi_state == osabi_user)
247 return user_selected_osabi;
249 /* If we don't have a binary, just return unknown. The caller may
250 have other sources the OSABI can be extracted from, e.g., the
251 target description. */
252 if (abfd == NULL)
253 return GDB_OSABI_UNKNOWN;
255 match = GDB_OSABI_UNKNOWN;
256 match_specific = 0;
258 for (sniffer = gdb_osabi_sniffer_list; sniffer != NULL;
259 sniffer = sniffer->next)
261 if ((sniffer->arch == bfd_arch_unknown /* wildcard */
262 || sniffer->arch == bfd_get_arch (abfd))
263 && sniffer->flavour == bfd_get_flavour (abfd))
265 osabi = (*sniffer->sniffer) (abfd);
266 if (osabi < GDB_OSABI_UNKNOWN || osabi >= GDB_OSABI_INVALID)
268 internal_error
269 (__FILE__, __LINE__,
270 _("gdbarch_lookup_osabi: invalid OS ABI (%d) from sniffer "
271 "for architecture %s flavour %d"),
272 (int) osabi,
273 bfd_printable_arch_mach (bfd_get_arch (abfd), 0),
274 (int) bfd_get_flavour (abfd));
276 else if (osabi != GDB_OSABI_UNKNOWN)
278 /* A specific sniffer always overrides a generic sniffer.
279 Croak on multiple match if the two matches are of the
280 same class. If the user wishes to continue, we'll use
281 the first match. */
282 if (match != GDB_OSABI_UNKNOWN)
284 if ((match_specific && sniffer->arch != bfd_arch_unknown)
285 || (!match_specific && sniffer->arch == bfd_arch_unknown))
287 internal_error
288 (__FILE__, __LINE__,
289 _("gdbarch_lookup_osabi: multiple %sspecific OS ABI "
290 "match for architecture %s flavour %d: first "
291 "match \"%s\", second match \"%s\""),
292 match_specific ? "" : "non-",
293 bfd_printable_arch_mach (bfd_get_arch (abfd), 0),
294 (int) bfd_get_flavour (abfd),
295 gdbarch_osabi_name (match),
296 gdbarch_osabi_name (osabi));
298 else if (sniffer->arch != bfd_arch_unknown)
300 match = osabi;
301 match_specific = 1;
304 else
306 match = osabi;
307 if (sniffer->arch != bfd_arch_unknown)
308 match_specific = 1;
314 return match;
318 /* Return non-zero if architecture A can run code written for
319 architecture B. */
320 static int
321 can_run_code_for (const struct bfd_arch_info *a, const struct bfd_arch_info *b)
323 /* BFD's 'A->compatible (A, B)' functions return zero if A and B are
324 incompatible. But if they are compatible, it returns the 'more
325 featureful' of the two arches. That is, if A can run code
326 written for B, but B can't run code written for A, then it'll
327 return A.
329 struct bfd_arch_info objects are singletons: that is, there's
330 supposed to be exactly one instance for a given machine. So you
331 can tell whether two are equivalent by comparing pointers. */
332 return (a == b || a->compatible (a, b) == a);
336 void
337 gdbarch_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch)
339 struct gdb_osabi_handler *handler;
341 gdb_assert (info.osabi != GDB_OSABI_UNKNOWN);
343 for (handler = gdb_osabi_handler_list; handler != NULL;
344 handler = handler->next)
346 if (handler->osabi != info.osabi)
347 continue;
349 /* If the architecture described by ARCH_INFO can run code for
350 the architecture we registered the handler for, then the
351 handler is applicable. Note, though, that if the handler is
352 for an architecture that is a superset of ARCH_INFO, we can't
353 use that --- it would be perfectly correct for it to install
354 gdbarch methods that refer to registers / instructions /
355 other facilities ARCH_INFO doesn't have.
357 NOTE: kettenis/20021027: There may be more than one machine
358 type that is compatible with the desired machine type. Right
359 now we simply return the first match, which is fine for now.
360 However, we might want to do something smarter in the future. */
361 /* NOTE: cagney/2003-10-23: The code for "a can_run_code_for b"
362 is implemented using BFD's compatible method (a->compatible
363 (b) == a -- the lowest common denominator between a and b is
364 a). That method's definition of compatible may not be as you
365 expect. For instance the test "amd64 can run code for i386"
366 (or more generally "64-bit ISA can run code for the 32-bit
367 ISA"). BFD doesn't normally consider 32-bit and 64-bit
368 "compatible" so it doesn't succeed. */
369 if (can_run_code_for (info.bfd_arch_info, handler->arch_info))
371 (*handler->init_osabi) (info, gdbarch);
372 return;
376 if (info.osabi == GDB_OSABI_NONE)
378 /* Don't complain about no OSABI. Assume the user knows
379 what they are doing. */
380 return;
383 warning
384 ("A handler for the OS ABI \"%s\" is not built into this configuration\n"
385 "of GDB. Attempting to continue with the default %s settings.\n",
386 gdbarch_osabi_name (info.osabi),
387 info.bfd_arch_info->printable_name);
390 /* Limit on the amount of data to be read. */
391 #define MAX_NOTESZ 128
393 /* Return non-zero if NOTE matches NAME, DESCSZ and TYPE. If
394 *SECTSIZE is non-zero, then this reads that many bytes from
395 the start of the section and clears *SECTSIZE. */
397 static int
398 check_note (bfd *abfd, asection *sect, char *note, unsigned int *sectsize,
399 const char *name, unsigned long descsz, unsigned long type)
401 unsigned long notesz;
403 if (*sectsize)
405 if (!bfd_get_section_contents (abfd, sect, note, 0, *sectsize))
406 return 0;
407 *sectsize = 0;
410 /* Calculate the size of this note. */
411 notesz = strlen (name) + 1;
412 notesz = ((notesz + 3) & ~3);
413 notesz += descsz;
414 notesz = ((notesz + 3) & ~3);
416 /* If this assertion triggers, increase MAX_NOTESZ. */
417 gdb_assert (notesz <= MAX_NOTESZ);
419 /* Check whether SECT is big enough to contain the complete note. */
420 if (notesz > bfd_section_size (sect))
421 return 0;
423 /* Check the note name. */
424 if (bfd_h_get_32 (abfd, note) != (strlen (name) + 1)
425 || strcmp (note + 12, name) != 0)
426 return 0;
428 /* Check the descriptor size. */
429 if (bfd_h_get_32 (abfd, note + 4) != descsz)
430 return 0;
432 /* Check the note type. */
433 if (bfd_h_get_32 (abfd, note + 8) != type)
434 return 0;
436 return 1;
439 /* Generic sniffer for ELF flavoured files. */
441 void
442 generic_elf_osabi_sniff_abi_tag_sections (bfd *abfd, asection *sect,
443 enum gdb_osabi *osabi)
445 const char *name;
446 unsigned int sectsize;
447 char *note;
449 name = bfd_section_name (sect);
450 sectsize = bfd_section_size (sect);
452 /* Limit the amount of data to read. */
453 if (sectsize > MAX_NOTESZ)
454 sectsize = MAX_NOTESZ;
456 /* We lazily read the section data here. Since we use
457 BFD_DECOMPRESS, we can't use bfd_get_section_contents on a
458 compressed section. But, since note sections are not compressed,
459 deferring the reading until we recognize the section avoids any
460 error. */
461 note = (char *) alloca (sectsize);
463 /* .note.ABI-tag notes, used by GNU/Linux and FreeBSD. */
464 if (strcmp (name, ".note.ABI-tag") == 0)
466 /* GNU. */
467 if (check_note (abfd, sect, note, &sectsize, "GNU", 16, NT_GNU_ABI_TAG))
469 unsigned int abi_tag = bfd_h_get_32 (abfd, note + 16);
471 switch (abi_tag)
473 case GNU_ABI_TAG_LINUX:
474 *osabi = GDB_OSABI_LINUX;
475 break;
477 case GNU_ABI_TAG_HURD:
478 *osabi = GDB_OSABI_HURD;
479 break;
481 case GNU_ABI_TAG_SOLARIS:
482 *osabi = GDB_OSABI_SOLARIS;
483 break;
485 case GNU_ABI_TAG_FREEBSD:
486 *osabi = GDB_OSABI_FREEBSD;
487 break;
489 case GNU_ABI_TAG_NETBSD:
490 *osabi = GDB_OSABI_NETBSD;
491 break;
493 default:
494 warning (_("GNU ABI tag value %u unrecognized."), abi_tag);
495 break;
497 return;
500 /* FreeBSD. */
501 if (check_note (abfd, sect, note, &sectsize, "FreeBSD", 4,
502 NT_FREEBSD_ABI_TAG))
504 /* There is no need to check the version yet. */
505 *osabi = GDB_OSABI_FREEBSD;
506 return;
509 return;
512 /* .note.netbsd.ident notes, used by NetBSD. */
513 if (strcmp (name, ".note.netbsd.ident") == 0
514 && check_note (abfd, sect, note, &sectsize, "NetBSD", 4, NT_NETBSD_IDENT))
516 /* There is no need to check the version yet. */
517 *osabi = GDB_OSABI_NETBSD;
518 return;
521 /* .note.openbsd.ident notes, used by OpenBSD. */
522 if (strcmp (name, ".note.openbsd.ident") == 0
523 && check_note (abfd, sect, note, &sectsize, "OpenBSD", 4,
524 NT_OPENBSD_IDENT))
526 /* There is no need to check the version yet. */
527 *osabi = GDB_OSABI_OPENBSD;
528 return;
531 /* .note.netbsdcore.procinfo notes, used by NetBSD. */
532 if (strcmp (name, ".note.netbsdcore.procinfo") == 0)
534 *osabi = GDB_OSABI_NETBSD;
535 return;
539 static enum gdb_osabi
540 generic_elf_osabi_sniffer (bfd *abfd)
542 unsigned int elfosabi;
543 enum gdb_osabi osabi = GDB_OSABI_UNKNOWN;
545 elfosabi = elf_elfheader (abfd)->e_ident[EI_OSABI];
547 switch (elfosabi)
549 case ELFOSABI_NONE:
550 case ELFOSABI_GNU:
551 case ELFOSABI_HPUX:
552 /* When the EI_OSABI field in the ELF header is ELFOSABI_NONE
553 (0), then the ELF structures in the file are conforming to
554 the base specification for that machine (there are no
555 OS-specific extensions). In order to determine the real OS
556 in use, we must look for OS-specific notes.
558 The same applies for ELFOSABI_GNU: this can mean GNU/Hurd,
559 GNU/Linux, and possibly more. */
561 /* And likewise ELFOSABI_HPUX. For some reason the default
562 value for the EI_OSABI field is ELFOSABI_HPUX for all PA-RISC
563 targets (with the exception of GNU/Linux). */
564 for (asection *sect : gdb_bfd_sections (abfd))
565 generic_elf_osabi_sniff_abi_tag_sections (abfd, sect, &osabi);
566 break;
568 case ELFOSABI_FREEBSD:
569 osabi = GDB_OSABI_FREEBSD;
570 break;
572 case ELFOSABI_NETBSD:
573 osabi = GDB_OSABI_NETBSD;
574 break;
576 case ELFOSABI_SOLARIS:
577 osabi = GDB_OSABI_SOLARIS;
578 break;
580 case ELFOSABI_OPENVMS:
581 osabi = GDB_OSABI_OPENVMS;
582 break;
585 if (osabi == GDB_OSABI_UNKNOWN)
587 /* The FreeBSD folks have been naughty; they stored the string
588 "FreeBSD" in the padding of the e_ident field of the ELF
589 header to "brand" their ELF binaries in FreeBSD 3.x. */
590 if (memcmp (&elf_elfheader (abfd)->e_ident[8],
591 "FreeBSD", sizeof ("FreeBSD")) == 0)
592 osabi = GDB_OSABI_FREEBSD;
595 return osabi;
598 static void
599 set_osabi (const char *args, int from_tty, struct cmd_list_element *c)
601 struct gdbarch_info info;
603 if (strcmp (set_osabi_string, "auto") == 0)
604 user_osabi_state = osabi_auto;
605 else if (strcmp (set_osabi_string, "default") == 0)
607 user_selected_osabi = GDB_OSABI_DEFAULT;
608 user_osabi_state = osabi_user;
610 else
612 int i;
614 for (i = 1; i < GDB_OSABI_INVALID; i++)
616 enum gdb_osabi osabi = (enum gdb_osabi) i;
618 if (strcmp (set_osabi_string, gdbarch_osabi_name (osabi)) == 0)
620 user_selected_osabi = osabi;
621 user_osabi_state = osabi_user;
622 break;
625 if (i == GDB_OSABI_INVALID)
626 internal_error (__FILE__, __LINE__,
627 _("Invalid OS ABI \"%s\" passed to command handler."),
628 set_osabi_string);
631 /* NOTE: At some point (true multiple architectures) we'll need to be more
632 graceful here. */
633 gdbarch_info_init (&info);
634 if (! gdbarch_update_p (info))
635 internal_error (__FILE__, __LINE__, _("Updating OS ABI failed."));
638 static void
639 show_osabi (struct ui_file *file, int from_tty, struct cmd_list_element *c,
640 const char *value)
642 if (user_osabi_state == osabi_auto)
643 fprintf_filtered (file,
644 _("The current OS ABI is \"auto\" "
645 "(currently \"%s\").\n"),
646 gdbarch_osabi_name (gdbarch_osabi (get_current_arch ())));
647 else
648 fprintf_filtered (file, _("The current OS ABI is \"%s\".\n"),
649 gdbarch_osabi_name (user_selected_osabi));
651 if (GDB_OSABI_DEFAULT != GDB_OSABI_UNKNOWN)
652 fprintf_filtered (file, _("The default OS ABI is \"%s\".\n"),
653 gdbarch_osabi_name (GDB_OSABI_DEFAULT));
656 void _initialize_gdb_osabi ();
657 void
658 _initialize_gdb_osabi ()
660 if (strcmp (gdb_osabi_names[GDB_OSABI_INVALID].pretty, "<invalid>") != 0)
661 internal_error
662 (__FILE__, __LINE__,
663 _("_initialize_gdb_osabi: gdb_osabi_names[] is inconsistent"));
665 /* Register a generic sniffer for ELF flavoured files. */
666 gdbarch_register_osabi_sniffer (bfd_arch_unknown,
667 bfd_target_elf_flavour,
668 generic_elf_osabi_sniffer);
670 /* Register the "set osabi" command. */
671 add_setshow_enum_cmd ("osabi", class_support, gdb_osabi_available_names,
672 &set_osabi_string,
673 _("Set OS ABI of target."),
674 _("Show OS ABI of target."),
675 NULL, set_osabi, show_osabi,
676 &setlist, &showlist);
677 user_osabi_state = osabi_auto;